The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of ten equations of state including linear polynomial, JWL high explosive, Sack "Tuesday" high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interfaces data for contact surfaces.

A contact-impact algorithm permits gaps and sliding along material interfaces with friction. All versions except for the IBM3090 include an interface type defining one-way treatment of sliding with voids and friction. By a specialization of this algorithm, such interfaces can be rigidly tied to admit variable zoning with no need for transition regions. Spatial discretization is achieved by implementation of Hughes-Liu rectangular beams and shells, Belytschko-Tsay shells and beams, triangular shell elements based on work by Belytschko and colleagues, and 8-node solid-shell elements. All element classes can be included as parts of a rigid body. Three-dimensional plane stress constitutive subroutines update the stress tensor for the shell elements such that the stress component normal to the shell midsurface is zero. One constitutive evaluation is made for each integration point through the shell thickness. The 8-node solid element uses either one point integration or the Flanagan and Belytschko constant stress formulation with exact volume integration. Zero energy modes in the shell and solid elements are controlled by either an hourglass viscosity of stiffness. The equations of motion are integrated in time by the central difference method. A Jaumann stress rate formulation is used with the exception of the orthotropic elastic and the rubber material subroutines which use Green-St.Venant strains to compute second Piola-Kirchoff stresses which transform to Gauchy stresses.

Execution speeds on the Cray X-MP for various DYNA3D element types range from 4 to 48 microseconds per element cycle. These timings are approximate and do not account for the inclusion of sliding interfaces or complex material models. Typical problems require from 4 to 80 minutes on the Cray X-MP.

The soil and crushable foam, linear viscoelastic, and the rubber Blatz-Ko subroutines were adapted from HONDO and recoded for vectorization, the ignition and growth EOS was adapted from KOVEC. The forms of the first five equations of state are from KOVEC also. The three-dimensional contact-impact algorithm is an extension of the NIKE2D (NESC9923) two-dimensional algorithm. The tied and sliding only interface options are similar to the two- dimensional algorithm used in DYNA2D (NESC9910). DYNA3D relies on stand-alone mesh generators. INGRID (NESC9649) is recommended for creation of input files, since it provides complete support for all slide surface data, boundary conditions, loads, material properties, and control parameters. The compatible release of TAURUS (NESC9908) processes DYNA3D output plotting contours, fringes, time histories, and deformed shapes. A variety of strain measures, reaction forces along constrained boundaries, and momenta can be computed.